Technology manufacturers need you to upgrade all your tech every year, so that you (and not them) pay for their R&D (research and development) in order to obtain a quick ROI (Return On Investment) for their troubles.
After all what good are you to them if you're their customer only once?
The need you to purchase this year's flagship smartphone with a multicoloured notification LED.
This year's software update may have a minimal feature update, features that have been designed years ago and turned off by default, but you have to download it now!
With regards to your personal computer, you could be running a 6 or 8 year old processor, and according to the 'mainstream' you must update, because your hardware is 'ancient', but do you really need to update?
Well that depends on what you're doing.
See more in the following video:
In reality consumers are getting blatantly ripped off by corporations profiteering from minimal updates making them out to be the next best/hottest feature you didn't know you needed.